1:2,400 Scale Hydrography Data Integration with NHD State of New Jersey 1:2,400 Scale Hydrography Data Integration with NHD By: Seth Hackman, GIS Specialist - NJDEP

2002 Aerial Photography Digital imagery produced by BAE/ADR. Keystone Aerial Surveys conducted the flyover. Images produced at 1:2,400 scale, 1 ft. pixel resolution, ground accuracy of +/- 4 ft. Imagery is available as an image service or for individual tile download through the NJ State Clearinghouse – NJGIN Also available from EROS Data Center

2002 Hydro Delineations Work was contracted to Aerial Information Systems (AIS) -- Redlands, CA. Hydro linework was done in conjunction with the 2002 land use/land cover update Previous GIS projects undertaken by AIS for State of NJ include: - Land Use/Land Cover 1986 - Land Use/Land Cover Update - 1995/97

NJ Hydrography Update Original 1986 Hydrography NHD 1:24,000 source was USGS quadrangle data as DLG’s Currently available for download (http://www.state.nj.us/dep/gis/listall.html) NHD 1:24,000 Used internally Good attribution 2002 Hydrography (1:2,400) Updated based on 2002 imagery Accurate stream data photo-interpreted (arcs) Water Body data layer delineated (polygonal)

Stream Data Layer Spec’s: Minimum mapping width for linear streams = 10 ft. Streams greater than 10 ft. but less than 30 ft. in width shall be delineated as a single line. Streams greater than 30 feet in width will be captured as polygons. The stream boundary will be delineated within +/- 5 feet of the land-water interface. For all polygonal streams, an artificial stream centerline (drainage path) will be digitized down the approximate middle of the polygon, with the correct arc/node topology that can be related to upstream and downstream flow direction analysis.

Resources of Delineation Time (and lots of it) Geography Staffing Money!!! The benefits far outweigh the problems!

Original Hydro from DLG’s © 1986 Statistics of Change: Original Hydro from DLG’s © 1986 vs. Streams 2002 (1:2,400)

1986 Hydrogrpahy (DLG’s)

1:24,000 NHD

2002 Hydrography 1:2,400

Stream Situation Code 0- River bank/Water body (>30ft) 1- Stream(10-30ft) 2- River/Water Body Centerline 3- Artificial Connector 4- Ditches 5- Indeterminate Wetland drainage

Water Body data layer (polygonal) The minimum mapping unit for non-linear water bodies is 1-acre. The minimum width for capturing linear water bodies as polygons is 30 feet. Water bodies captured as polygons have been delineated within +/- 5 feet of the land-water interface as interpreted on the 2002 imagery. Water polygons delivered as separate layer

Current Lakes & Streams

New Lakes & Streams

Integration with NHD Our intent is to: Implement NHD using one pilot watershed in NJ (using EPA grant funding) Pass NHD24K attributes to new linework. Add new codes to new delineated streams found NHD24K. Use the 1:2,400 hydrography network for NJ as the “NHD Layer” for the state.

What’s Next? Produce NHD stewardship agreement between State of NJ and USGS. Get trained in the latest tools and technologies for attribute transfer and coding for new stream lines. Network with other states to share experiences and determine the best way forward. Incorporate the needs of NJDEP Water Programs to add new themes and features to NHD Model for NJ.

Thanks! Contact Info: NJDEP, Bureau of GIS Website: http://www.nj.gov/dep/gis Phone: (609) 777-0672 E-mail: gisnet@dep.state.nj.us Seth Hackman – Project Manager Phone: 609-633-1262 E-mail: seth.hackman@dep.state.nj.us